diff options
| -rw-r--r-- | drivers/of/base.c | 109 | ||||
| -rw-r--r-- | drivers/of/gpio.c | 81 | ||||
| -rw-r--r-- | include/linux/of.h | 3 |
3 files changed, 131 insertions, 62 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index cd1ce7ab851..4270eb4a26a 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -458,3 +458,112 @@ int of_modalias_node(struct device_node *node, char *modalias, int len) } EXPORT_SYMBOL_GPL(of_modalias_node); +/** + * of_parse_phandles_with_args - Find a node pointed by phandle in a list + * @np: pointer to a device tree node containing a list + * @list_name: property name that contains a list + * @cells_name: property name that specifies phandles' arguments count + * @index: index of a phandle to parse out + * @out_node: pointer to device_node struct pointer (will be filled) + * @out_args: pointer to arguments pointer (will be filled) + * + * This function is useful to parse lists of phandles and their arguments. + * Returns 0 on success and fills out_node and out_args, on error returns + * appropriate errno value. + * + * Example: + * + * phandle1: node1 { + * #list-cells = <2>; + * } + * + * phandle2: node2 { + * #list-cells = <1>; + * } + * + * node3 { + * list = <&phandle1 1 2 &phandle2 3>; + * } + * + * To get a device_node of the `node2' node you may call this: + * of_parse_phandles_with_args(node3, "list", "#list-cells", 2, &node2, &args); + */ +int of_parse_phandles_with_args(struct device_node *np, const char *list_name, + const char *cells_name, int index, + struct device_node **out_node, + const void **out_args) +{ + int ret = -EINVAL; + const u32 *list; + const u32 *list_end; + int size; + int cur_index = 0; + struct device_node *node = NULL; + const void *args; + + list = of_get_property(np, list_name, &size); + if (!list) { + ret = -ENOENT; + goto err0; + } + list_end = list + size / sizeof(*list); + + while (list < list_end) { + const u32 *cells; + const phandle *phandle; + + phandle = list; + args = list + 1; + + /* one cell hole in the list = <>; */ + if (!*phandle) { + list++; + goto next; + } + + node = of_find_node_by_phandle(*phandle); + if (!node) { + pr_debug("%s: could not find phandle\n", + np->full_name); + goto err0; + } + + cells = of_get_property(node, cells_name, &size); + if (!cells || size != sizeof(*cells)) { + pr_debug("%s: could not get %s for %s\n", + np->full_name, cells_name, node->full_name); + goto err1; + } + + /* Next phandle is at offset of one phandle cell + #cells */ + list += 1 + *cells; + if (list > list_end) { + pr_debug("%s: insufficient arguments length\n", + np->full_name); + goto err1; + } +next: + if (cur_index == index) + break; + + of_node_put(node); + node = NULL; + cur_index++; + } + + if (!node) { + ret = -ENOENT; + goto err0; + } + + *out_node = node; + *out_args = args; + + return 0; +err1: + of_node_put(node); +err0: + pr_debug("%s failed with status %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL(of_parse_phandles_with_args); diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c index 1c9cab844f1..7cd7301b583 100644 --- a/drivers/of/gpio.c +++ b/drivers/of/gpio.c @@ -28,78 +28,35 @@ */ int of_get_gpio(struct device_node *np, int index) { - int ret = -EINVAL; + int ret; struct device_node *gc; struct of_gpio_chip *of_gc = NULL; int size; - const u32 *gpios; - u32 nr_cells; - int i; const void *gpio_spec; const u32 *gpio_cells; - int gpio_index = 0; - gpios = of_get_property(np, "gpios", &size); - if (!gpios) { - ret = -ENOENT; + ret = of_parse_phandles_with_args(np, "gpios", "#gpio-cells", index, + &gc, &gpio_spec); + if (ret) { + pr_debug("%s: can't parse gpios property\n", __func__); goto err0; } - nr_cells = size / sizeof(u32); - - for (i = 0; i < nr_cells; gpio_index++) { - const phandle *gpio_phandle; - - gpio_phandle = gpios + i; - gpio_spec = gpio_phandle + 1; - - /* one cell hole in the gpios = <>; */ - if (!*gpio_phandle) { - if (gpio_index == index) - return -ENOENT; - i++; - continue; - } - - gc = of_find_node_by_phandle(*gpio_phandle); - if (!gc) { - pr_debug("%s: could not find phandle for gpios\n", - np->full_name); - goto err0; - } - - of_gc = gc->data; - if (!of_gc) { - pr_debug("%s: gpio controller %s isn't registered\n", - np->full_name, gc->full_name); - goto err1; - } - - gpio_cells = of_get_property(gc, "#gpio-cells", &size); - if (!gpio_cells || size != sizeof(*gpio_cells) || - *gpio_cells != of_gc->gpio_cells) { - pr_debug("%s: wrong #gpio-cells for %s\n", - np->full_name, gc->full_name); - goto err1; - } - - /* Next phandle is at phandle cells + #gpio-cells */ - i += sizeof(*gpio_phandle) / sizeof(u32) + *gpio_cells; - if (i >= nr_cells + 1) { - pr_debug("%s: insufficient gpio-spec length\n", - np->full_name); - goto err1; - } - - if (gpio_index == index) - break; - - of_gc = NULL; - of_node_put(gc); - } + of_gc = gc->data; if (!of_gc) { - ret = -ENOENT; - goto err0; + pr_debug("%s: gpio controller %s isn't registered\n", + np->full_name, gc->full_name); + ret = -ENODEV; + goto err1; + } + + gpio_cells = of_get_property(gc, "#gpio-cells", &size); + if (!gpio_cells || size != sizeof(*gpio_cells) || + *gpio_cells != of_gc->gpio_cells) { + pr_debug("%s: wrong #gpio-cells for %s\n", + np->full_name, gc->full_name); + ret = -EINVAL; + goto err1; } ret = of_gc->xlate(of_gc, np, gpio_spec); diff --git a/include/linux/of.h b/include/linux/of.h index 79886ade070..e2488f5e7cb 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -71,5 +71,8 @@ extern int of_n_size_cells(struct device_node *np); extern const struct of_device_id *of_match_node( const struct of_device_id *matches, const struct device_node *node); extern int of_modalias_node(struct device_node *node, char *modalias, int len); +extern int of_parse_phandles_with_args(struct device_node *np, + const char *list_name, const char *cells_name, int index, + struct device_node **out_node, const void **out_args); #endif /* _LINUX_OF_H */ |